The present invention relates to systems for treating vascular lesions and in particular to treating saphenous vein graft lesions (SVGs).
One of the most common surgical procedures performed to treat blocked coronary vessels is to bypass the blockage with a vein that is harvested from another portion of a patient""s body. The most common veins used are the saphenous veins, which are two large superficial veins of the leg. While this procedure works well to restore blood flow around the heart, it is often the case that these saphenous vein grafts (SVGs) become occluded themselves in a relatively short period of time.
For some physiological reason, which is not completely understood, lesions occurring in an SVG tend to be loosely formed and fragile. These fragile lesions are difficult to treat with conventional intravascular techniques because the lesion may fragment and occlude a vessel further downstream, such as in the brain. Therefore, many patient""s must undergo another bypass surgery to restore blood flow to the heart. Given the frequency with which SVGs become occluded, there is a need for a less invasive technique for treating them.
The present invention is a technique for treating vessels that are occluded with loosely formed, friable lesions such as the type that occur in saphenous vein grafts. To treat a lesion, the lesion is isolated in a vessel and drugs or medications are delivered to the isolated portion of the vessel that solidify the lesion. Once solidified, the lesion can be treated with any number of conventional intravascular surgical techniques such as atherectomy, balloon angioplasty, etc.
In accordance with an embodiment of the invention, one or more inflatable balloons are positioned distal to and proximal from the lesion to be treated. The balloons are inflated to isolate the lesion and an embolizing drug or medication is delivered to the isolated area between the balloons in order to solidify a lesion. Once solidified, the balloons are deflated and removed. Next, the solidified lesion can be treated with a conventional intravascular technique.